2 midi.c -- implement Python midi parser module
4 source file of the GNU LilyPond music typesetter
6 (c) 2001 Han-Wen Nienhuys <hanwen@cs.uu.nl>
7 Jan Nieuwenhuizen <janneke@gnu.org>
15 s = open ("s.midi").read ()
24 #if HAVE_PYTHON2_PYTHON_H
25 #include <python2/Python.h>
26 #elif HAVE_PYTHON2_2_PYTHON_H
27 #include <python2.2/Python.h>
28 #elif HAVE_PYTHON2_1_PYTHON_H
29 #include <python2.1/Python.h>
30 #elif HAVE_PYTHON2_0_PYTHON_H
31 #include <python2.0/Python.h>
32 #elif HAVE_PYTHON1_5_PYTHON_H
33 #include <python1.5/Python.h>
34 #elif HAVE_PYTHON_PYTHON_H
36 #include <python/Python.h>
47 #define debug_print(f, args...) fprintf (stderr, "%s:%d: track: %p :" f, __FUNCTION__, __LINE__, *track, ##args)
49 #define debug_print(f, args...)
52 static PyObject *Midi_error;
53 static PyObject *Midi_warning;
56 midi_error (char * func, char *s)
58 char*dest = (char*) malloc (sizeof (char) * (strlen (func) + strlen (s) + 1));
61 PyErr_SetString (Midi_error, dest);
68 midi_warning (char *s)
70 PyErr_SetString (Midi_warning, s);
75 typedef struct message {
80 message_t channelVoiceMessages[] = {
83 0xA0, "POLYPHONIC_KEY_PRESSURE",
84 0xB0, "CONTROLLER_CHANGE",
85 0xC0, "PROGRAM_CHANGE",
86 0xD0, "CHANNEL_KEY_PRESSURE",
91 message_t channelModeMessages[] = {
92 0x78, "ALL_SOUND_OFF",
93 0x79, "RESET_ALL_CONTROLLERS",
94 0x7A, "LOCAL_CONTROL",
95 0x7B, "ALL_NOTES_OFF",
96 0x7C, "OMNI_MODE_OFF",
103 message_t metaEvents[] = {
104 0x00, "SEQUENCE_NUMBER",
106 0x02, "COPYRIGHT_NOTICE",
107 0x03, "SEQUENCE_TRACK_NAME",
108 0x04, "INSTRUMENT_NAME",
112 0x20, "MIDI_CHANNEL_PREFIX",
114 0x2F, "END_OF_TRACK",
116 0x54, "SMTPE_OFFSET",
117 0x58, "TIME_SIGNATURE",
118 0x59, "KEY_SIGNATURE",
119 0x7F, "SEQUENCER_SPECIFIC_META_EVENT",
125 add_constants (PyObject *dict)
127 message_t * p[] = {metaEvents, channelModeMessages, channelVoiceMessages ,0};
129 for ( j =0; p[j]; j++)
130 for ( i = 0; p[j][i].description; i++)
131 PyDict_SetItemString (dict, p[j][i].description, Py_BuildValue ("i", p[j][i].msg));
135 get_number (unsigned char ** str, unsigned char * end_str, int length)
137 /* # MIDI uses big-endian for everything */
141 for (; i < length; i++)
142 sum = (sum << 8) + (unsigned char) (*str)[i];
145 debug_print ("%d:\n", sum);
150 get_variable_length_number (unsigned char **str, unsigned char * end_str)
154 while (*str < end_str)
156 unsigned char x = **str;
158 sum = (sum << 7) + (x & 0x7F);
162 debug_print ("%d:\n", sum);
167 read_one_byte (unsigned char **track, unsigned char *end,
170 PyObject *pyev = Py_BuildValue ("(i)", x);
171 debug_print ("%x:%s", x, "event\n");
177 read_two_bytes (unsigned char **track, unsigned char *end,
180 PyObject *pyev = Py_BuildValue ("(ii)", x, (*track)[0]);
182 debug_print ("%x:%s", x, "event\n");
187 read_three_bytes (unsigned char **track, unsigned char *end,
190 PyObject *pyev = Py_BuildValue ("(iii)", x, (*track)[0],
194 debug_print ("%x:%s", x, "event\n");
199 read_string (unsigned char **track, unsigned char *end)
201 unsigned long length = get_variable_length_number (track, end);
202 if (length > end - *track)
203 length = end - *track;
206 return Py_BuildValue ("s#", ((*track) -length), length);
209 typedef PyObject* (*Read_midi_event)
210 (unsigned char **track, unsigned char *end,
215 read_f0_byte (unsigned char **track, unsigned char *end,
219 debug_print ("%x:%s", x, "event\n");
222 unsigned char z = (*track)[0 ];
224 debug_print ("%x:%s", z, "f0-event\n");
226 return Py_BuildValue ("(iiO)", x, z, read_string (track, end));
229 return Py_BuildValue ("(iO)", x, read_string (track, end));
232 Read_midi_event read_midi_event [16] =
240 read_one_byte, // 60 data entry.
241 read_two_bytes, // 70 all notes off
242 read_three_bytes, // 80 note off
243 read_three_bytes, // 90 note on
244 read_three_bytes, // a0 poly aftertouch
245 read_three_bytes, // b0 control
246 read_two_bytes, // c0 prog change
247 read_two_bytes, // d0 ch aftertouch
248 read_three_bytes, // e0 pitchwheel range
254 read_event (unsigned char **track, unsigned char *end, PyObject *time,
255 unsigned char *running_status)
257 int rsb_skip = ((**track & 0x80)) ? 1 :0;
259 unsigned char x = (rsb_skip) ? (*track)[0]: *running_status;
261 PyObject * bare_event = 0;
262 debug_print ("%x:%s", x, "event\n");
266 // printf ("%x %x %d next %x\n", x, (*track)[0], rsb_skip, (*track)[1]);
267 bare_event = (*read_midi_event[x >> 4]) (track, end, x);
269 return Py_BuildValue ("(OO)", time, bare_event);
275 midi_parse_track (unsigned char **track, unsigned char *track_end)
277 unsigned int time = 0;
278 unsigned char running_status;
279 unsigned long track_len, track_size;
280 PyObject *pytrack = 0;
282 debug_print ("%s", "\n");
284 track_size = track_end - *track;
286 debug_print ("%s", "\n");
287 if (strcmp (*track, "MTrk"))
288 return midi_error (__FUNCTION__, ": MTrk expected");
292 track_len = get_number (track, *track + 4, 4);
295 debug_print ("track_len: %u\n", track_len);
296 debug_print ("track_size: %u\n", track_size);
297 debug_print ("track begin: %p\n", track);
298 debug_print ("track end: %p\n", track + track_len);
300 if (track_len > track_size)
301 return midi_error (__FUNCTION__, ": track size corrupt");
303 pytrack = PyList_New (0);
305 track_end = *track + track_len;
308 PyObject *pytime = PyInt_FromLong (0L);
309 while (*track < track_end)
311 long dt = get_variable_length_number(track, track_end);
316 pytime = PyInt_FromLong (time);
318 pyev = read_event (track, track_end, pytime,
321 PyList_Append (pytrack, pyev);
331 pymidi_parse_track (PyObject *self, PyObject *args)
333 unsigned char *track, *track_end;
334 unsigned long track_size, track_len;
336 PyObject * sobj = PyTuple_GetItem (args, 0);
338 debug_print ("%s", "\n");
339 if (!PyArg_ParseTuple (args, "s#", &track, &track_size))
343 return midi_error (__FUNCTION__, ": negative track size");
345 track_end = track + track_size;
347 return midi_parse_track (&track, track_end);
351 midi_parse (unsigned char **midi,unsigned char *midi_end)
353 PyObject *pymidi = 0;
354 unsigned long header_len;
355 unsigned format, tracks;
359 debug_print ("%s", "\n");
362 header_len = get_number (midi, *midi + 4, 4);
366 return midi_error (__FUNCTION__, ": header too short");
368 format = get_number (midi, *midi + 2, 2);
369 tracks = get_number (midi, *midi + 2, 2);
372 return midi_error (__FUNCTION__, ": too many tracks");
374 division = get_number (midi, *midi + 2, 2) * 4;
378 /* return midi_error ("can't handle non-metrical time"); */
380 *midi += header_len - 6;
382 pymidi = PyList_New (0);
385 for (i = 0; i < tracks; i++)
386 PyList_Append (pymidi, midi_parse_track (midi, midi_end));
388 pymidi = Py_BuildValue ("(OO)", Py_BuildValue ("(ii)", format, division),
394 pymidi_parse (PyObject *self, PyObject *args)
396 unsigned char *midi, *midi_end;
397 unsigned long midi_size, midi_len;
399 PyObject *sobj = PyTuple_GetItem (args, 0);
401 debug_print ("%s", "\n");
402 if (!PyArg_ParseTuple (args, "s#", &midi, &midi_size))
405 if (strcmp (midi, "MThd"))
406 return midi_error (__FUNCTION__, ": MThd expected");
410 midi_end = midi + midi_size;
412 return midi_parse (&midi, midi_end);
416 static PyMethodDef MidiMethods[] =
418 {"parse", pymidi_parse, 1},
419 {"parse_track", pymidi_parse_track, 1},
420 {0, 0} /* Sentinel */
426 m = Py_InitModule ("midi", MidiMethods);
427 d = PyModule_GetDict (m);
429 Midi_error = PyString_FromString ("midi.error");
430 PyDict_SetItemString (d, "error", Midi_error);
432 Midi_warning = PyString_FromString ("midi.warning");
433 PyDict_SetItemString (d, "warning", Midi_warning);